What’s New for CSS in Beta 2 Preview?

We have heard all your feedback asking us for full CSS compliance. With the now public available Beta 2 Preview build on XP, we get a big step closer to this goal. Chris talked about our priorities for IE7 before, but I want to give more detail on our work with CSS. We had 3 objectives, in priority:

Fix some really nasty bugs posted on sites like positioniseverything.net

Revise parts of our existing CSS implementation to be true to the spec

As we were implementing attribute selectors we also added support for CSS 3 attribute selectors: prefix, suffix and substring.

Compatibility and our updated CSS behavior

Obviously, we have heard the feedback asking us to be more standards-compliant in our rendering behavior. We must balance this ask with the need of our customers (and end users) to have their pages not be broken. To find a balance we introduced a strict mode in IE6 that lets authors opt in into the more standards compliant rendering (and, if you’re putting in a modern DOCTYPE declaration, you’re being opted in automatically). Pages authored under non-strict mode (or “quirks mode”) will not change behavior in IE7 – so the fixes we’ve done to be more CSS compliant won’t appear under quirks mode. However, if your content is under “strict mode”, our behavior is more standards compliant, and your pages may break - for example, if you use some of the CSS hacks or rely on our old incorrect overflow behavior. We understand the pain this might cause in the short term but we believe a move to a more standard compliant implementation benefits everyone in the long run.

Last but not least, big thanks to the community: here on the blog (yes, we are paying attention to the comments), the WASP team and those out on the webreporting CSS issues with IE. We know we have a long road ahead but I am very excited with the progress we are making.